Segment Information - Reconciliation of U.S. GAAP Loss Before Income Taxes to Adjusted EBITDA (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting [Abstract]
Adjusted EBITDA		$ 15,454	$ 6,829	$ 75,565	$ 69,859
Stock-based compensation expense		(20,526)	(22,710)	(66,423)	(62,524)
Interest expense		(1,529)	(1,566)	(4,583)	(2,851)
Depreciation and amortization		(9,783)	(8,273)	(29,271)	(24,092)
Special adjustments, interest income and other	[1]	5,481	(2,949)	7,480	(20,878)
Loss before income taxes		$ (10,903)	$ (28,669)	$ (17,232)	$ (40,486)

[1] The three months ended September 30, 2023, includes $4.8 million of interest income, a $3.5 million gain from the mark-to-market adjustment of contingent consideration associated with the World Programming acquisition, and $2.8 million of currency losses on acquisition-related intercompany loans. The three months ended September 30, 2022, includes $6.8 million currency losses on acquisition-related intercompany loans, a $2.2 million gain from the mark-to-market adjustment of contingent consideration associated with the World Programming acquisition, and $1.7 million of interest income. The nine months ended September 30, 2023, includes $11.7 million of interest income, a $4.5 million loss from the mark-to-market adjustment of contingent consideration associated with the World Programming acquisition, and $0.3 million of currency gains on acquisition-related intercompany loans. The nine months ended September 30, 2022, includes $16.6 million expense on repurchase of convertible senior notes, $13.7 million of currency losses on acquisition-related intercompany loans, a $7.5 million gain from the mark-to-market adjustment of contingent consideration associated with the World Programming acquisition, and $2.0 million of interest income.